1. Field of the Invention
The present invention relates to a combination switch including a push switch section having a contact plate elastically deformable with a pressing operation and a contacted point that enters into an electrically conductive state upon contact with the contact plate, the push switch section being configured to detect the pressing operation, and a rotary switch section having a brush unit comprised of a rotary conductive member rotatable about an axis with a lever operation and a plurality of contact shoes formed on the rotary conductive member and a plurality of fixed contacts electrically conductive with the plurality of contact shoes, the rotary switch section being configured to detect a rotary operation.
2. Description of the Related Art
A combination switch having the above-described construction is disclosed in Japanese Patent Application “Kokai” No. 2008-177098. This combination switch includes a lower main body and an upper frame. The push switch section is disposed at a position exposed through a hole defined at the center of the frame. The combination switch further includes a lever protruding laterally from between the main body and the frame. At the center of the top face of the main body, there are provided a plurality of fixed contacts for the push switch section, and at a position upwardly of the fixed contacts, there is provided an electrode plate that is elastically deformable with a pressing force to render a fixed electrode conductive. At positions equidistant from the center of the top face of the main body, there are provided the plurality of fixed contacts for the rotary switch section. There is provided a ring-shaped bush having a plurality of contact shoes contactable with the fixed contacts and this bush is operably coupled with a lever.
With the above-described construction, when a pressing operation is effected to the push switch section, the electrode plate is elastically deformed, so that the fixed electrode is rendered conductive, thus detecting this pressing operation. Whereas, when a rotary (or pivotal) operating force is applied to the lever, the contact shoes of the brush come into selective contact with the fixed electrode for the rotary switch, so that the rotary operating force can be detected in two steps, one being in the clockwise rotational direction, the other being in the counter-clockwise rotational direction.
With this combination switch disclosed in the Japanese Patent Application “Kokai” No. 2008-177098, as the fixed contacts for the rotary switch in particular, there are provided one common contact and two fixed contacts for the detecting of the clockwise rotation and for the counterclockwise rotation, respectively. On the other hand, the brush includes four contact shoes for the ring-shaped fixed portion, these four contact shoes corresponding to the two individual contacts for the detection of the clockwise rotation and the two individual contacts for the detection of the counterclockwise rotation.
With the above-described construction, when the brush is rotated clockwise from the neutral position, relative to the two individual contacts provided for detection of clockwise rotation, the associated contact shoes come into contact one after another and one of the contact shoes provided for the detection of the counter-clockwise rotation is maintained under contact with the common contact. Conversely, when the brush is rotated counter-clockwise from the neutral position, relative to the two individual contacts provided for detection of counter-clockwise rotation, the associated contact shoes come into contact one after another and one of the contact shoes provided for the detection of the clockwise rotation is maintained under contact with the common contact. In this way, the rotational operation of the lever can be detected in the two steps for the clockwise rotation and the counter-clockwise rotation, respectively.
With the combination switch disclosed in the Japanese Patent Application “Kokai” No. 2008-177098, four contact shoes are formed for the brush and the plurality of fixed contacts (i.e. the individual contacts and the common contact) are disposed at the positions corresponding respectively thereto. As such, the plurality of fixed contacts are arranged over a large cylindrical area relative to the rotational center. Further, for enabling the rotational angle of the rotary operation by an appropriate pitch, the distance between adjacent fixed contacts (the peripheral distance relative to the center) needs to be set at a relatively large value. For these reasons, the fixed contacts are disposed in distribution over the large cylindrical area, thus making it difficult to form the combination switch compact.
In view of the above, the object of the present invention is to form compact the combination switch capable of detecting a pressing operation and capable of detecting also a rotational operation in two directions, one in a predetermined direction, the other in the direction opposite thereto.